The recently retired director of the United States National Security Agency says Australia was correct to exclude Chinese telecommunications manufacturer Huawei from helping build the national broadband network because of evidence of Chinese espionage against the nation.

Keith Alexander, arguably the world’s most important cyber spy at the time of the previous Labor government’s ban on Huawei, described it as a “tremendous” decision and suggested UK officials who permitted Huawei to work on similar projects may now regret that decision.

It is the second time a high-ranking US security figure has weighed in on the debate, which was criticised by many as excessive and needlessly damaging to Australian trade relations with China.

“I think they made the right decision and I applaud them for that. There have been numerous examples that your country has seen where China has exploited various parts of your nation’s government and commercial activities. Giving them access to your nation’s network does not make sense.”

The decision upset Beijing and was opposed by some senior government members. Communications Minister Malcolm Turnbull and Foreign Minister Julie Bishop backed revisiting the move.

General Alexander said if the UK government spoke to Australian intelligence agencies and reviewed the processes Australia went through to reach the Huawei decision, it might change its approach if it had its time again.

Claims of hypocrisy

Critics have pointed to hypocrisy in banning Chinese tech suppliers when revelations by former NSA contractor Edward Snowden have highlighted the role some US-based companies play in aiding US surveillance. General Alexander said the comparison was not valid.

“The close ties between the Chinese government and industry are in no way comparable to the relations between the US government and US industry,” he said.

He said media controversy over disclosures of surveillance under the PRISM program could jeopardise US industry sales and threatened the reputation of some of the US’s most important companies. The NSA had failed some of these organisations by not setting the record straight about misconceptions of their role in spying. “NSA should have done more to set the record straight sooner on companies’ commitment to protecting privacy, the lengths to which companies go to do this, the legally compelled nature of these programs, and that these companies comply with the law,” he said.

“We must explain to the public that our foreign intelligence collection programs do not involve the tech companies indiscriminately providing wholesale information to the government, and those companies and our government are heavily constrained by the courts, Congress and the executive branch.”

He said the FAA 702 program, which compels US tech companies to provide information to the intelligence community, was similar and often less extensive than programs in other Western countries. Greens Senator Scott Ludlum, a vocal critic of the NSA, said General Alexander’s defence of its practices was difficult to believe. “I think all that Mr Alexander is engaging in here is an act of damage control, but the fact is there is a lot of damage. We have had people as senior as [US director of national intelligence] James Clapper outright lying to congressional committees about the activities of the NSA. The NSA’s activities have been found to be unlawful and it was acting well outside of its mandate.”